Report of the EGSE reduced data of the EPIC MOS FM2 calibration at Orsay

The aim of the present document is to describe the test configuration set up and the content of the Erdf DAT Tapes containing all the Erdf data produced during the calibration campaign of the FM2 MO

Report of the EGSE reduced data of the EPIC PN FM1 calibration at Orsay

The aim of the present document is to describe the test configuration set up and the content of the Erdf DAT Tapes containing all the Erdf data produced during the calibration campaign of the FM1 P

Signal compensation in CZT detectors grown by the Vertical Bridgman method using a twin-shaping filter technique

CdTe/CZT is now a material consolidated for the detectors realization operating at room temperature, which find a large variety of applications in astrophysics, medical imaging and security. An Italian collaboration, involving the CNR/IMEM and INAF/IASF institutes, was born several years ago with the aim to develop a national capability to produce CZT detectors starting from the material growth to the final detection device. The collection efficiency of the charge carriers affects some important features of these detectors, such as the pulse height, energy resolution, photopeak efficiency. In fact the low mobility of the charge carriers (particularly the holes) and trapping/detrapping phenomena can degrade the CdTe/CZT detector response, depending on the distance between the charge formation position and the collecting electrodes. Two kinds of techniques can be used to improve both the collection efficiency and the energy resolution, based on the optimization of the electrode geometry and/or signal compensation methods. We have implemented a biparametric method that uses a twin pulse shaping active filter to analyze the same signal from the detector: one “slow”, which is proportional to the energy of the incident photon, and one “fast”, which depends on the position of the interaction with respect to the collecting electrode. We present this biparametric technique applied on planar CZT detectors grown by the Vertical Bridgman method at CNR/IMEM (Parma), the experimental results obtained as a function of the bias voltage, photon energy, shaping time pairs and the compensated spectra

Survey of ophthalmologists-in-training in Eastern, Central and Southern Africa: A regional focus on ophthalmic surgical education.

Background: There are 2.7 ophthalmologists per million population in sub-Saharan Africa, and a need to train more. We sought to analyse current surgical training practice and experience of ophthalmologists to inform planning of training in Eastern, Central and Southern Africa. Methods: This was a cross-sectional survey. Potential participants included all current trainee and recent graduate ophthalmologists in the Eastern, Central and Southern African region. A link to a web-based questionnaire was sent to all heads of eye departments and training programme directors of ophthalmology training institutions in Eastern, Central and Southern Africa, who forwarded to all their trainees and recent graduates. Main outcome measures were quantitative and qualitative survey responses. Results: Responses were obtained from 124 (52%) trainees in the region. Overall level of satisfaction with ophthalmology training programmes was rated as 'somewhat satisfied' or 'very satisfied' by 72%. Most frequent intended career choice was general ophthalmology, with >75% planning to work in their home country post-graduation. A quarter stated a desire to mainly work in private practice. Only 28% of junior (first and second year) trainees felt surgically confident in manual small incision cataract surgery (SICS); this increased to 84% among senior trainees and recent graduates. The median number of cataract surgeries performed by junior trainees was zero. 57% of senior trainees were confident in performing an anterior vitrectomy. Only 29% of senior trainees and 64% of recent graduates were confident in trabeculectomy. The mean number of cataract procedures performed by senior trainees was 84 SICS (median 58) and 101 phacoemulsification (median 0). Conclusion: Satisfaction with post-graduate ophthalmology training in the region was fair. Most junior trainees experience limited cataract surgical training in the first two years. Focused efforts on certain aspects of surgical education should be made to ensure adequate opportunities are offered earlier on in ophthalmology training

Intense Simulation-Based Surgical Education for Manual Small-Incision Cataract Surgery: The Ophthalmic Learning and Improvement Initiative in Cataract Surgery Randomized Clinical Trial in Kenya, Tanzania, Uganda, and Zimbabwe.

Importance: Cataracts account for 40% of cases of blindness globally, with surgery the only treatment. Objective: To determine whether adding simulation-based cataract surgical training to conventional training results in improved acquisition of surgical skills among trainees. Design, Setting, and Participants: A multicenter, investigator-masked, parallel-group, randomized clinical educational-intervention trial was conducted at 5 university hospital training institutions in Kenya, Tanzania, Uganda, and Zimbabwe from October 1, 2017, to September 30, 2019, with a follow-up of 15 months. Fifty-two trainee ophthalmologists were assessed for eligibility (required no prior cataract surgery as primary surgeon); 50 were recruited and randomized. Those assessing outcomes of surgical competency were masked to group assignment. Analysis was performed on an intention-to-treat basis. Interventions: The intervention group received a 5-day simulation-based cataract surgical training course, in addition to standard surgical training. The control group received standard training only, without a placebo intervention; however, those in the control group received the intervention training after the initial 12-month follow-up period. Main Outcomes and Measures: The primary outcome measure was overall surgical competency at 3 months, which was assessed with a validated competency assessment rubric. Secondary outcomes included surgical competence at 1 year and quantity and outcomes (including visual acuity and posterior capsule rupture) of cataract surgical procedures performed during a 1-year period. Results: Among the 50 participants (26 women [52.0%]; mean [SD] age, 32.3 [4.6] years), 25 were randomized to the intervention group, and 25 were randomized to the control group, with 1 dropout. Forty-nine participants were included in the final intention-to-treat analysis. Baseline characteristics were balanced. The participants in the intervention group had higher scores at 3 months compared with the participants in the control group, after adjusting for baseline assessment rubric score. The participants in the intervention group were estimated to have scores 16.6 points (out of 40) higher (95% CI, 14.4-18.7; P < .001) at 3 months than the participants in the control group. The participants in the intervention group performed a mean of 21.5 cataract surgical procedures in the year after the training, while the participants in the control group performed a mean of 8.5 cataract surgical procedures (mean difference, 13.0; 95% CI, 3.9-22.2; P < .001). Posterior capsule rupture rates (an important complication) were 7.8% (42 of 537) for the intervention group and 26.6% (54 of 203) for the control group (difference, 18.8%; 95% CI, 12.3%-25.3%; P < .001). Conclusions and Relevance: This randomized clinical trial provides evidence that intense simulation-based cataract surgical education facilitates the rapid acquisition of surgical competence and maximizes patient safety. Trial Registration: Pan-African Clinical Trial Registry, number PACTR201803002159198

Compton polarimetry with a multi-layer CdTe focal plane prototype

In high-energy astrophysics, polarimetry is a promising subject with a wide scientific potential that is relatively unexplored due to the complexity of the design and technical requirements of the sensors. Often gamma-ray telescope proposals are based on multi-layer spectro-imager instruments with polarimetric capabilities. Herein we study a new Compton polarimeter prototype based on a two-layer CdTe pixelized spectro-imager operated in coincidence. The two CdTe detectors are 2 mm thick anode 8 ×8 pixels' segmented matrices with 2 mm pitch. This detection system configuration allows an assessment of the polarimetric potential of multi-layer solution focal planes as well as the polarimetric potential of a possible 3D spectro-imager by analysing the polarimetric performance when varying the distance between the two CdTe detection layers. The polarimetric modulation factors for single-layer (Q ∼0.4) and two-layer (up to 0.13) double-events were measured for 6 mm and for 10 mm distance between planes. The measured polarization angle resolution was lower than 10°. The potential of CdTe spectro-imager focal plane solutions with polarimetric capabilities for the next generation space missions based on both Laue lenses and 3D segmented focal planes is also discussed

Twin-Shaping Filter Technique Applied to CZT Detectors

CdTe/CdZnTe is an attractive and consolidated material with which to realize detectors with good efficiency and energy resolution, operating at room temperature for a large variety of applications such as astrophysics, medical imaging and security. However, this type of material suffers from the low mobility of the charge carriers (particularly the holes), which are trapped and so degrade the detector response in terms of charge collection efficiency, energy resolution and photopeak efficiency. The response of a planar CdTe/CdZnTe detector, which depends on the distance between the charge formation position and the collecting electrodes, can be improved by using two kinds of techniques, based on the optimization of the electrode geometry and/or signal compensation methods. We are studying the feasibility and the reliability of a biparametric method that uses a twin pulse shaping active filter to analyze each signal from the detector twice: one “Slow”, which is proportional to the energy of the incident photon, and one “Fast”, which depends on the position of the interaction with respect to the collecting electrode. In this paper we describe the bi-parametric technique applied to planar CdZnTe detectors grown by CNR/IMEM and to Spectrometer Grade detectors. We report the experimental results in terms of energy resolution, peak-to valley ratio and photopeak efficiency, as well as the compensated spectra obtained as a function of the bias voltage, photon energy and shaping time pairs. We also report the results obtained by using a CdZnTe drift strip detector. Furthermore, this technique could be implemented in an array of detectors, whose front-end electronics is composed of ASICs, where the shaping time can be selected for each channel, like the RENA-3 IC (NOVA R&D)

Experiences and Perceptions of Ophthalmic Simulation-Based Surgical Education in Sub-Saharan Africa.

BACKGROUND: Simulation-based surgical education (SBSE) can positively impact trainee surgical competence. However, a detailed qualitative study of the role of simulation in ophthalmic surgical education has not previously been conducted. OBJECTIVE: To explore the experiences of trainee ophthalmologists and ophthalmic surgeon educators' use of simulation, and the perceived challenges in surgical training. METHODS: A multi-center, multi-country qualitative study was conducted between October 2017 and August 2020. Trainee ophthalmologists from six training centers in sub-Saharan Africa (SSA) (in Kenya, Uganda, Tanzania, Zimbabwe and South Africa) participated in semi-structured interviews, before and after an intense simulation training course in intraocular surgery. Semi-structured interviews were also conducted with experienced ophthalmic surgeon educators. Interviews were anonymized, recorded, transcribed and coded. An inductive, bottom-up, constant comparative method was used for thematic analysis. RESULTS: Twenty-seven trainee ophthalmologists and 12 ophthalmic surgeon educators were included in the study and interviewed. The benefits and challenges of conventional surgical teaching, attributes of surgical educators, value of simulation in training and barriers to implementing ophthalmic surgical simulation were identified as major themes. Almost all trainees and trainers reported patient safety, a calm environment, the possibility of repetitive practice, and facilitation of reflective learning as beneficial aspects of ophthalmic SBSE. Perceived barriers in surgical training included a lack of surgical cases, poor supervision and limited simulation facilities. CONCLUSIONS: Simulation is perceived as an important and valuable model for education amongst trainees and ophthalmic surgeon educators in SSA. Advocating for the expansion and integration of educationally robust simulation surgical skills centers may improve the delivery of ophthalmic surgical education throughout SSA

Ophthalmology training in sub-Saharan Africa: a scoping review.

Sub-Saharan Africa is home to 12% of the global population, and 4.3 million are blind and over 15 million are visually impaired. There are only 2.5 ophthalmologists per million people in SSA. Training of ophthalmologists is critical. We designed a systematic literature review protocol, searched MEDLINE Ovid and Embase OVID on 1 August 2019 and limited these searches to the year 2000 onwards. We also searched Google Scholar and websites of ophthalmic institutions for additional information. We include a total of 49 references in this review and used a narrative approach to synthesise the results. There are 56 training institutions for ophthalmologists in eleven Anglophone, eleven Francophone, and two Lusophone SSA countries. The median duration of ophthalmology training programmes was 4 years. Most curricula have been regionally standardised. National, regional and international collaborations are a key feature to ophthalmology training in more than half of ophthalmology training programmes. There is a drive, although perhaps not always evidence-based, for sub-specialisation in the region. Available published scientific data on ophthalmic medical and surgical training in SSA is sparse, especially for Francophone and Lusophone countries. However, through a broad scoping review strategy it has been possible to obtain a valuable and detailed view of ophthalmology training in SSA. Training of ophthalmologists is a complex and multi-faceted task. There are challenges in appropriate selection, capacity, and funding of available training institutions. Numerous learning outcomes demand curriculum, time, faculty, support, and appropriate assessment. There are opportunities provided by modern training approaches. Partnership is key

Focussing crystals for use in broad band hard X/soft gamma-ray Laue lenses

Hard X-/soft gamma-ray astronomy is a crucial window for the study of the most energetic and violent events in the Universe. To fulfil the scientific requirements in this regime, a new generation of telescopes with a broad operational band extending from tens up to several hundreds of keV and exploiting unprecedented sensitivity (50-100 times better that current instruments) is required. We report on diffractive bent crystals made of Gallium Arsenide (GaAs) that are suitable for the construction of high sensitivity X-/gamma-ray Laue lens space telescopes. Laue lenses, made of sets of diffractive crystals working in transmission, offer one possibility, albeit technically challenging, to build a new generation of focusing telescopes that can extend the energy band far beyond the 80 keV limit for current multilayer concentrators. In particular, we present the results obtained from the characterization of crystals that will be used to realise a broad band Laue demonstrator. They have been studied in terms of focusing capability and diffraction efficiency by using a flat X-ray panel imager and an HPGe spectrometer as focal plane detectors. The GaAs tiles, bent via a surface lapping procedure, have been developed at the IMEM/CNR in Parma (Italy) in the framework of the LAUE project funded by the Italian Space Agency. The main goal of the project was to build a broad band Laue lens demonstrator for hard X-/soft gamma-rays (80-300 keV